I have a 3'x5' area in my crawlspace that I want to form a sump pit out of concrete, but I'm unsure how to form it.

I'd like to have a 16"x16"x 1' deep square catch basin in the middle and have the rest of the concrete have a slight slope so that any water it catches will be directed to the sump.

I could use a plastic container for the middle basin, but would prefer the concrete approach.

Right now I'm thinking of a 2 stage pour.
1) Pour the top slab by making a form in the middle to define the area for the catch basin

2) Dig down a foot+ in the middle. Pour the bottom later of the catch basin. Place a box on the base concrete and then fill the outsides of the box to the top of the slab.

Does this sound reasonable, or is there a way to do it in a single pour?

Ron6519

05-01-2010 06:14 PM

You can purchase sump basins and just insert them into the slab. If you still want to build your own, 12" is too shallow. I would make it 16"-18" deep.
Ron

RoyalAcresRod

05-02-2010 07:38 AM

Just asking.....why would you want to go to all the trouble and mess of pouring concrete in a crawl space? I can not see the benefit to all that additional work.

I had water problems in mine: Purchased a Little Giant crawl space kit that comes with pump and plastic "pit."

Dug the pit, gravel in first 4-8 inches..pit it, then filled with gravel surrounding pit approx 6 inch circumference around pit. I also dug channels leading to the pit, using 2 inch perf pipe and gravel.

What is the purpose of the concrete?

ror

walkman

05-02-2010 04:19 PM

Quote:

Originally Posted by RoyalAcresRod
(Post 436429)

Just asking.....why would you want to go to all the trouble?

ror

I pulled out 50 yards of dirt from the crawlspace portion of my basement and created a 13'x15' utility area with 8' ceiling. It has a slab floor and 5' high block retaining walls on 3 sides. I still have a 5' wide area of crawlspace along the front of the house that leaked water when we had very heavy rains earlier this year.

I want to be able to capture any flooding from the crawlspace area before it could reach the slab, plus have a way to exit water from my humidier, or from a water heater overflow, etc.

RoyalAcresRod

05-02-2010 05:06 PM

Well that makes a little more sense. I was envisioning a short crawl, and couldn't understand why you'd want to go to the trouble of concrete.

I would prepare the pump pit approx 3 ft wide by at least 3 ft deep. Put about 6 inches of gravel on bottom, put in sump pit, and then surround the remainder with gravel to about 2-3 inches of surface, then form the perimeter with 1X or 2x lumber...then make the pour.

If there are supplemental areas you want to drain to pit, put those pipes in so that they drain to pit before you pour.

rod

jgipp

05-03-2010 12:25 AM

catch basin

A five gallon pail set in a concrete pad works, but depending on how much water you get, probably not the best way. If you get a constant flow, it would be better to have a 20 gal pumpout then a 5 gal to be easier on the pump. Also, a check valve is important if pumping upward. Not an expert, just my experiences

RoyalAcresRod

05-03-2010 08:05 AM

Little Giant makes several pre-packaged sump systems complete with pump, pit, and check valve. I've used a number of their systems and have been quite satisfied. All are available for online purchase.

Rod

stadry

05-03-2010 12:53 PM

we buy the 30" tall sumps, ck valves, & zoeller pumps from ferguson supply ( $ 235 +/- ) then install the sump on 6" of 1 1/2"- stone,,, surround w/stone, then place 3" of conc around the sump,,, that's our normal install & most pro's do the same,,, good luck !

jimmy21

05-03-2010 02:47 PM

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i agree with everyone else. Why not just use plastic, and then dig trenches and fill with drain rock to capture any water and lead it to the pump?